High-Cost CFD on a Low-Cost Cluster

Direct numerical simulation of the Navier-Stokes equations (DNS) is an important technique for the future of computational fluid dynamics (CFD) in engineering applications. However, DNS requires massive computing resources. This paper presents a new approach for implementing high-cost DNS CFD using low-cost cluster hardware. After describing the DNS CFD code DNSTool, the paper focuses on the techniques and tools that we have developed to customize the performance of a cluster implementation of this application. This tuning of system performance involves both recoding of the application and careful engineering of the cluster design. Using the cluster KLAT2 (Kentucky Linux Athlon Testbed 2), while DNSTool cannot match the $0.64 per MFLOPS that KLAT2 achieves on single precision ScaLAPACK, it is very efficient; DNSTool on KLAT2 achieves price/performance of $2.75 per MFLOPS double precision and $1.86 single precision. Further, the code and tools are all, or will soon be, made freely available as full source code.